US5537024A - Circuit arrangement to detect a voltage - Google Patents

Circuit arrangement to detect a voltage Download PDF

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Publication number
US5537024A
US5537024A US08/204,398 US20439894A US5537024A US 5537024 A US5537024 A US 5537024A US 20439894 A US20439894 A US 20439894A US 5537024 A US5537024 A US 5537024A
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United States
Prior art keywords
voltage
circuit arrangement
output
divider
voltage detector
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Expired - Fee Related
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US08/204,398
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English (en)
Inventor
Gerhard Lang
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Braun GmbH
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Braun GmbH
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Assigned to BRAUN AKTIENGESELLSCHAFT reassignment BRAUN AKTIENGESELLSCHAFT ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: LANG, GERHARD
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Publication of US5537024A publication Critical patent/US5537024A/en
Assigned to BRAUN GMBH reassignment BRAUN GMBH CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: BRAUN AKTIENGESELLSCHAFT
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16533—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the application
    • G01R19/16538—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the application in AC or DC supplies
    • G01R19/16542—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the application in AC or DC supplies for batteries
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/04—Voltage dividers
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/36—Arrangements for testing, measuring or monitoring the electrical condition of accumulators or electric batteries, e.g. capacity or state of charge [SoC]
    • G01R31/3644—Constructional arrangements
    • G01R31/3648—Constructional arrangements comprising digital calculation means, e.g. for performing an algorithm
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S320/00—Electricity: battery or capacitor charging or discharging
    • Y10S320/18—Indicator or display
    • Y10S320/21—State of charge of battery

Definitions

  • This invention relates to a circuit arrangement to detect a voltage, including a voltage divider having applied to its divider node the input of a voltage detector which comprises a Schmitt-Trigger with reference voltage and an output driver, with the output of the voltage detector being connected to the positive potential of the voltage.
  • FIG. 4 illustrates the wiring of such a voltage detector VD when a specified voltage, for example, the voltage of two serially connected battery cells or accumulator cells (B), is to be detected which is greater than the internal reference voltage of the voltage detector VD.
  • a voltage divider comprised of resistors R1 and R4 is connected in parallel with the battery B, and the junction of the two resistors R1 and R4 is connected to the IN input of the voltage detector VD.
  • the OUT output of the voltage detector VD is applied to the positive potential of the battery B through a resistor R2.
  • the voltage divider R1/R4 is so dimensioned that the internal reference voltage (2.1 volts, for example) will be present at the IN input of the voltage detector VD when the voltage to be detected (2.3 volts, for example) is present at the battery B. When the battery voltage drops below-this value, the output of the voltage comparator VD will go from "high” to "low".
  • this object is accomplished in that the output signal of the voltage detector is applied to the base of a first transistor, that the collector-emitter circuit, together with a series-connected capacitor, is connected in parallel with the voltage to be detected, that the junction of the capacitor and the first transistor is connected to the input of the voltage detector through a first resistor, and that the output of the voltage detector is further applied to the input of a component delivering different output signals in dependence upon whether its input receives a constant signal level or a varying signal level.
  • the resistor of the first voltage divider connected to reference potential is comprised of a second voltage divider to which an integrating capacitor is connected in parallel and whose divider node receives a square-wave voltage whose pulse duty factor is variable.
  • FIG. 1 is a schematic diagram showing a circuit arrangement for detecting a specified voltage value on a battery
  • FIGS. 2 and 3 are schematic diagrams showing circuit arrangements for detecting several voltage values using a single voltage detector; and FIG. 4 is a schematic diagram of a commercially available voltage detector.
  • FIG. 1 of the drawings there is shown a circuit arrangement providing a suitable indication when the voltage U of the battery B has reached a specified value.
  • a load resistor RL may be connected to this battery (accumulator) through a switch S.
  • This load resistor may be the motor of a small electrical appliance as, for example, an electric shaver.
  • the battery is rechargeable by means of a charging circuitry not shown.
  • a voltage divider comprised of resistors R1 and R4, by means of which the voltage U of the battery B is divided down to the voltage Ue residing at the junction of the resistors R1 and R4 which is applied to the IN input of the voltage detector VD.
  • the OUT output of the voltage detector VD is connected to the positive terminal of the battery B through a resistor R2, to the base of a transistor T1 through a resistor R3, and to the microprocessor C driving a display device D through a resistor R10.
  • the emitter of transistor T1 is connected to the positive terminal of the battery B, its collector being connected to reference potential through a capacitor C1.
  • the collector is connected to the junction of the resistors R1 and R4 of the voltage divider through resistors R5 and R6.
  • the resistor R6 is of the variable type for adjustment.
  • the voltage divider R1/R4 is dimensioned such as to ensure that, when the battery B reaches a specified voltage U, the divided-down voltage Ue at the IN input of the voltage detector VD lies below the detection voltage of the voltage detector VD.
  • This specified voltage U may be, for example, the "low charge” point at 2.3 volts (in which event the battery is discharged to 10% to 20% of its capacity).
  • the detection voltage of the voltage detector is, for example, 2.1 volts and the tolerance is ⁇ 0.1 volts (which has no relation to the hysteresis of the voltage detector), these are 2.0 volts.
  • the mode of function of the circuit arrangement is as follows: When the battery voltage U has dropped to the voltage to be detected which is, for example, 2.3 volts, the voltage Ue at the IN input of the voltage detector VD will be 2.0 volts, and the OUT output of the voltage detector VD will change from “high” to “low”. "Low” is the active state of the voltage detector VD. Transistor T1 will then conduct, causing the series arrangement comprised of the resistors R5, R6 to be connected in parallel with resistor R1. The input voltage Ue (divider voltage) is thereby increased to a value greater than the detection voltage of the voltage detector plus the hysteresis voltage, causing the voltage detector to assume the reverse state again (release voltage) and the OUT output to return to "high". The transistor T1 is again non-conducting, cancelling the parallel connection of resistors R5, R6 to resistor R1, whereby the divider voltage Ue is again below the detection voltage of the voltage detector VD, and the OUT output is again changed to "low
  • the circuitry oscillates.
  • the capacitor C1 provides time delays for the transition operations, thus reducing the oscillation frequency to about 1 kHz, for example.
  • a square-wave voltage with an amplitude of the order of the battery voltage U is present at the OUT output.
  • a specified value of the supply voltage solely by the presence of a constant signal level at the output of the voltage detector VD with respect to a varying (oscillating) voltage level.
  • the specified voltage value is detected without hysteresis, that is, it is irrelevant whether the specified voltage value is reached starting from higher or from lower voltage values, since it is not the internal reference voltage of the voltage detector (2.1 volts) that is used for adjustment, but rather its release voltage.
  • FIGS. 2 and 3 present an extension of FIG. 1 to cover the detection of several voltages using just a single voltage detector VD.
  • the resistor R4 of FIG. 1 is subdivided into serially connected resistors R7, R8 and R9, whereof resistor R7 is connected to the input of the voltage detector VD, while resistor R9 is tied to reference potential.
  • An integrating capacitor C2 is connected in parallel with the series arrangement comprised of resistors R8 and R9.
  • an output of the microprocessor C is connected to the junction of resistors R8 and R9.
  • the microprocessor supplies to this junction a square-wave control signal whose pulse duty factor is variable.
  • the release voltage point of the voltage detector VD can be shifted over a wide range of the voltage U of the battery B.
  • the greater the pulse duty factor of the square-wave voltage supplied that is, the greater the pulse/no-pulse ratio, the higher the mean value of the voltage supplied.
  • the voltage at the junction of capacitor C2 and resistor R8, and consequently also the voltage Ue at the input of the voltage detector VD are raised, whereby the release voltage of the voltage detector is reached at higher battery voltages U.
  • the current charging condition of the battery is displayed.
  • the segments are controlled by the microprocessor C such that in the fully charged condition (highest detected voltage), all segments are driven, whilst with the battery charge near depletion (lowest detected voltage), no segment is driven.
  • the display device D provides a continuous indication of the charging condition on a time basis, that is, in dependence on the period of time during which the load resistor RL (load) was connected to the battery or the battery was charged, the voltage points detected in operation will be compared to the values of the battery charging and discharging characteristic stored in the microprocessor, and if a deviation is established, the display will be corrected correspondingly.
  • FIG. 3 shows a circuit arrangement suitable for the event that the voltage divider is not sufficiently high-resistance, that is, the output of the microprocessor C supplying the square-wave voltage is not in a position to provide the requisite power.
  • the square-wave signal of the microprocessor C will be delivered through a resistor R11 to the base of a transistor T2 whose collector-emitter circuit is in parallel with the resistor R9.
  • the transistor T2 is rendered either conducting or non-conducting.
  • the mode of function of the circuit arrangement is the same as that of FIG. 2.
  • circuit arrangements described in the foregoing are self-oscillating, requiring no control voltages from an external source. In consequence of the low current requirements, the circuit arrangements may remain connected to the supply voltage U also with the appliance turned off (load resistor RL disconnected from the battery), without the battery discharging unacceptably.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Current Or Voltage (AREA)
  • Tests Of Electric Status Of Batteries (AREA)
  • Emergency Protection Circuit Devices (AREA)
US08/204,398 1991-09-20 1992-07-30 Circuit arrangement to detect a voltage Expired - Fee Related US5537024A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE4131417.4 1991-09-20
DE4131417A DE4131417C1 (enrdf_load_stackoverflow) 1991-09-20 1991-09-20
PCT/DE1992/000642 WO1993006492A1 (de) 1991-09-20 1992-07-30 Schaltungsanordnung zur erfassung einer spannung

Publications (1)

Publication Number Publication Date
US5537024A true US5537024A (en) 1996-07-16

Family

ID=6441126

Family Applications (1)

Application Number Title Priority Date Filing Date
US08/204,398 Expired - Fee Related US5537024A (en) 1991-09-20 1992-07-30 Circuit arrangement to detect a voltage

Country Status (7)

Country Link
US (1) US5537024A (enrdf_load_stackoverflow)
EP (1) EP0604444B1 (enrdf_load_stackoverflow)
JP (1) JPH06510852A (enrdf_load_stackoverflow)
AT (1) ATE127931T1 (enrdf_load_stackoverflow)
DE (2) DE4131417C1 (enrdf_load_stackoverflow)
HK (1) HK97196A (enrdf_load_stackoverflow)
WO (1) WO1993006492A1 (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6081436A (en) * 1998-08-12 2000-06-27 Lucent Technologies, Inc. Multi-output power supply voltage sensing
WO2000065683A3 (en) * 1999-04-23 2001-04-05 Procter & Gamble Consumer battery having a built-in indicator
US6545510B1 (en) 2001-12-10 2003-04-08 Micron Technology, Inc. Input buffer and method for voltage level detection
US6781442B2 (en) * 2000-09-08 2004-08-24 Mitsubishi Denki Kabushiki Kaisha Self-bias adjustment circuit
US20130057409A1 (en) * 2011-09-05 2013-03-07 Fluke Corporation Watchdog For Voltage Detector Display
US20170358934A1 (en) * 2016-06-08 2017-12-14 Eaton Corporation Battery Management Systems Having Battery Failure Detection and Related Methods and Uninterruptible Power Supplies (UPSs)
US20180299492A1 (en) * 2015-08-19 2018-10-18 Siemens Aktiengesellschaft Self-powered measuring apparatus and measurement method

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4334338B4 (de) * 1993-10-08 2006-07-27 Robert Bosch Gmbh Schaltung zur Überwachung der Versorgungsspannung einer integrierten Schaltung
FR2719123B1 (fr) * 1994-04-22 1996-06-28 Matra Mhs Dispositif de détection de la variation non transitoire d'une tension d'alimentation.
DE4437647A1 (de) * 1994-10-21 1996-05-02 Braun Ag Verfahren zur Bestimmung des Ladezustandes eines Akkumulators
DE102005063045A1 (de) 2005-12-29 2007-07-05 Braun Gmbh Entladezustandsanzeige
DE102008012546A1 (de) * 2008-03-04 2009-09-10 Robert Bosch Gmbh Vorrichtung zur Erfassung der Ausgangsspannung einer Batterie

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3670246A (en) * 1970-03-16 1972-06-13 Forbro Design Corp Under-voltage monitoring device having time delay means for regulated power supplies
US4429236A (en) * 1980-09-24 1984-01-31 Robert Bosch Gmbh Apparatus for generating pulses upon decreases in supply voltage
US4445090A (en) * 1981-08-26 1984-04-24 Towmotor Corporation Voltage level monitoring and indicating apparatus
US4758772A (en) * 1986-07-09 1988-07-19 Braun Aktiengesellschaft Discharge indicating means for a storage battery
US4829290A (en) * 1988-01-04 1989-05-09 Motorola, Inc. Low voltage alert circuit
US4906055A (en) * 1987-04-02 1990-03-06 Sharp Kabushiki Kaisha Voltage level judging device

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3110135A (en) * 1961-11-06 1963-11-12 Holtzer Cabot Corp Gear cutting apparatus
DE2002651A1 (de) * 1969-02-26 1970-09-10 Leipzig Rft Fernmeldewerk Schwellwertschalter mit Sprungcharakteristik
DE2517138A1 (de) * 1975-04-18 1976-10-21 Stenocord Electronic Gmbh Schaltungsanordnung zur ueberwachung der versorgungsspannung batteriebetriebener geraete
FR2558265B1 (fr) * 1984-01-13 1986-06-20 Black & Decker Inc Dispositif de controle de la mise en charge d'un ensemble d'accumulateurs sur un systeme de charge independant
JPS6471620A (en) * 1987-09-10 1989-03-16 Nissan Motor Method for finishing gear
DE4033898A1 (de) * 1990-01-24 1991-07-25 Diehl Gmbh & Co Signaleinrichtung zur anzeige des fehlens einer elektrischen spannung
US5124627A (en) * 1990-02-07 1992-06-23 Sanyo Electric Co., Ltd. Battery capacity computing apparatus

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3670246A (en) * 1970-03-16 1972-06-13 Forbro Design Corp Under-voltage monitoring device having time delay means for regulated power supplies
US4429236A (en) * 1980-09-24 1984-01-31 Robert Bosch Gmbh Apparatus for generating pulses upon decreases in supply voltage
US4445090A (en) * 1981-08-26 1984-04-24 Towmotor Corporation Voltage level monitoring and indicating apparatus
US4758772A (en) * 1986-07-09 1988-07-19 Braun Aktiengesellschaft Discharge indicating means for a storage battery
US4906055A (en) * 1987-04-02 1990-03-06 Sharp Kabushiki Kaisha Voltage level judging device
US4829290A (en) * 1988-01-04 1989-05-09 Motorola, Inc. Low voltage alert circuit

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6081436A (en) * 1998-08-12 2000-06-27 Lucent Technologies, Inc. Multi-output power supply voltage sensing
WO2000065683A3 (en) * 1999-04-23 2001-04-05 Procter & Gamble Consumer battery having a built-in indicator
US6483275B1 (en) 1999-04-23 2002-11-19 The Board Of Trustees Of The Univesity Of Illinois Consumer battery having a built-in indicator
US6781442B2 (en) * 2000-09-08 2004-08-24 Mitsubishi Denki Kabushiki Kaisha Self-bias adjustment circuit
US6545510B1 (en) 2001-12-10 2003-04-08 Micron Technology, Inc. Input buffer and method for voltage level detection
US20130057409A1 (en) * 2011-09-05 2013-03-07 Fluke Corporation Watchdog For Voltage Detector Display
US9128129B2 (en) * 2011-09-05 2015-09-08 Fluke Corporation Watchdog for voltage detector display
US20180299492A1 (en) * 2015-08-19 2018-10-18 Siemens Aktiengesellschaft Self-powered measuring apparatus and measurement method
US10514397B2 (en) * 2015-08-19 2019-12-24 Siemens Aktiengesellschaft Self-powered measuring apparatus and measurement method
US20170358934A1 (en) * 2016-06-08 2017-12-14 Eaton Corporation Battery Management Systems Having Battery Failure Detection and Related Methods and Uninterruptible Power Supplies (UPSs)
US11165264B2 (en) * 2016-06-08 2021-11-02 Eaton Intelligent Power Limited Battery management systems having battery failure detection and related methods and uninterruptible power supplies (UPSs)

Also Published As

Publication number Publication date
DE4131417C1 (enrdf_load_stackoverflow) 1993-04-22
EP0604444B1 (de) 1995-09-13
JPH06510852A (ja) 1994-12-01
ATE127931T1 (de) 1995-09-15
DE59203699D1 (de) 1995-10-19
WO1993006492A1 (de) 1993-04-01
HK97196A (en) 1996-06-14
EP0604444A1 (de) 1994-07-06

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